The long range goal of this animal resource project is to enhance the ability of the Mount Desert Island Biological Laboratory (MDIBL) to provide marine species to investigators for use in basic biomedical and toxicological research. MDIBL is an international research center where visiting investigators make use of unique marine species to investigate the molecular mechanisms that underlie the basic function of organs such as the kidney, the liver, the brain, the heart and the ye. MDIBL is currently the year round home for one research program in Developmental Biology and a corporate laboratory, that is collaborating in the development of facility for rearing fish embryos and transgenic animals. The ability of MDIBL to provide marine animals such as the shark, skate, flounder, sculpin, killifish, crabs, sea urchins, sand dollars, and snails is entirely dependent on the continuous function of a seawater system which takes in seawater from Frenchman Bay and distributes it to individual laboratories and central hold facilities. The current seawater system is the result of several decades of gradual evolution, ad hoc repairs and alterations. As a consequence the current system is highly compromised by inadequate pumping and suboptimal distribution as well as aging components that have a high failure rate and cannot be easily maintained. Frequent failure of the system leads to the loss of specimens or maintenance in suboptimal conditions thus impairing the ability of the Lab to supply animals for research. The specific aims are 1) to upgrade the seawater intake system by installing high capacity, self priming pumps equipped with duplicate intake lines to permit periodic preventative maintenance; and to improve the safety and accessibility of the pumping stating; 2) to completely redesign and renovate the seawater distribution system to assure adequate flow rates to all laboratories and holding areas, and allow for duplicate lines that facilitate cleaning and prevent freezing of the lines in winter; 3) to renovate fish holding areas to increase the capacity and the quality control of the seawater and permit expanded seasonal and year-round use; and 4) to implement an expanded animal health program that will include increased monitoring of animal holding tans and veterinary supervision necessary for holding animals for long periods. The proposed renovation will enhance the ability of MDIBL to provide marine specimens to visiting investigators, permit expanded year- round use of the animal facility and provide the foundation for reestablishing a core facility for generating and maintaining transgenic mice.